DIRECTIONAL PROTECTIVE RELAY DEVICE AND DIRECTIONAL POWER RELAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a directional protective relay device and a directional power relay device capable of reducing the installation number of current transformers for protecting a three-phase AC circuit against a short-circuit fault or an inverse flow, and the numbers of directional protective relays and directional power relays.;SOLUTION: An R-phase and an S-phase of a power transmission line are led through an annular iron core of a three-phase through current transformer 10 installed on a power transmission line so as to be mutually inverse only one time, while the T-phase of the power transmission line is led through in the same direction as the R-phase two times. Upon detecting a short-circuit fault based on a short-circuit current I_Ry inputted from the three-phase through current transformer 10 and voltage information of the power transmission line, a short-circuit directional relay 4 collectively interrupts first-third breakers 2₁-2₃ installed on the R-phase, S-phase and T-phase of the power transmission line respectively.;COPYRIGHT: (C)2010,JPO&INPIT